/**
 * Copyright (C) 2009 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.inject.internal;

import static com.google.common.collect.Iterables.concat;

import com.google.common.collect.ImmutableList;
import com.google.inject.spi.InjectionPoint;

/**
 * Constructor injectors by type.
 *
 * @author jessewilson@google.com (Jesse Wilson)
 */
final class ConstructorInjectorStore {
    private final InjectorImpl injector;

    private final FailableCache<InjectionPoint, ConstructorInjector<?>> cache = new FailableCache<InjectionPoint, ConstructorInjector<?>>() {
        @Override
        protected ConstructorInjector<?> create(InjectionPoint constructorInjector, Errors errors) throws ErrorsException {
            return createConstructor(constructorInjector, errors);
        }
    };

    ConstructorInjectorStore(InjectorImpl injector) {
        this.injector = injector;
    }

    /**
     * Returns a new complete constructor injector with injection listeners registered.
     */
    public ConstructorInjector<?> get(InjectionPoint constructorInjector, Errors errors) throws ErrorsException {
        return cache.get(constructorInjector, errors);
    }

    /**
     * Purges an injection point from the cache. Use this only if the cache is not actually valid and
     * needs to be purged. (See issue 319 and
     * ImplicitBindingTest#testCircularJitBindingsLeaveNoResidue and
     * #testInstancesRequestingProvidersForThemselvesWithChildInjectors for examples of when this is
     * necessary.)
     * 
     * Returns true if the injector for that point was stored in the cache, false otherwise.
     */
    boolean remove(InjectionPoint ip) {
        return cache.remove(ip);
    }

    private <T> ConstructorInjector<T> createConstructor(InjectionPoint injectionPoint, Errors errors) throws ErrorsException {
        int numErrorsBefore = errors.size();

        SingleParameterInjector<?>[] constructorParameterInjectors = injector.getParametersInjectors(injectionPoint.getDependencies(), errors);

        @SuppressWarnings("unchecked") // the injector type agrees with the injection point type
        MembersInjectorImpl<T> membersInjector = (MembersInjectorImpl<T>) injector.membersInjectorStore.get(injectionPoint.getDeclaringType(), errors);

        /*if[AOP]*/
        ImmutableList<MethodAspect> injectorAspects = injector.state.getMethodAspects();
        ImmutableList<MethodAspect> methodAspects = membersInjector.getAddedAspects().isEmpty() ? injectorAspects : ImmutableList.copyOf(concat(injectorAspects, membersInjector.getAddedAspects()));
        ConstructionProxyFactory<T> factory = new ProxyFactory<T>(injectionPoint, methodAspects);
        /*end[AOP]*/
        /*if[NO_AOP]
        ConstructionProxyFactory<T> factory = new DefaultConstructionProxyFactory<T>(injectionPoint);
        end[NO_AOP]*/

        errors.throwIfNewErrors(numErrorsBefore);

        return new ConstructorInjector<T>(membersInjector.getInjectionPoints(), factory.create(), constructorParameterInjectors, membersInjector);
    }
}
